<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>04JS运算符</title>
</head>
<body>
<script>
    //除法会根据实际情况显示运算结果
    console.log(3/2);//1.5
    console.log(6/2);//3

    //如果比较运算符左右两边有数字，会转为数字在进行比较
    console.log(3>10);//false
    console.log(3>'10');//false
    console.log('3'>10);//false
    //如果比较运算符左右两边都是字符串，会比较他们的编码值
    console.log('3'>'10');//ture
    console.log('法'>'就');//ture
    console.log('3'.charCodeAt());//查看编码值 51
    console.log('10'.charCodeAt(0));//查看编码值 49
    console.log('10'.charCodeAt());//查看编码值 49

    //Number()将参数转为数字，如果得不到数值类型的结果，会得到Nan(not a number)
    console.log(Number('3'),typeof Number('3'));//3  number
    console.log(Number(true),typeof Number(true));//1 number
    console.log(Number(false),typeof Number(false));//0 number
    console.log(Number('你好'),typeof Number('你好'));//NaN  number

    let a = 1;
    let b = true;
    //松散比较运算符，只比较值，Number(true)=1
    console.log(a == b);//true
    //严格比较运算符，先比较类型，在比较值 number ≠ boolean
    console.log(a === b);//false

    //Boolean()将参数转为布尔类型的值
    //如果参数是0  空字符串  null  undefined  NaN  都会转为false
    console.log(Boolean(0))
    console.log(Boolean(''))
    console.log(Boolean(null))
    console.log(Boolean(undefined))
    console.log(Boolean(NaN))
    console.log(Boolean('  '))//ture
    console.log(Boolean('下午好!'))//ture

    //三元运算符
    let c = 0;
    console.log(c==0 ? 'yes' : 'no')//yes
    //=是赋值符号，给c赋值为0，Boolean(0)=false,所以取no
    console.log(c=0 ? 'yes' : 'no')//no
</script>
</body>
</html>